bug#56527: 28.1; Crash on macOS with magit

[Eli Zaretskii <eliz@gnu.org>]

> From: Jonathan Mitchell <mitchell.jkyle@gmail.com>
> Date: Thu, 14 Jul 2022 11:18:02 -0500
> Cc: 56527@debbugs.gnu.org
> 
> I think this should be the "m" variable in the assert:
> 
> (lldb) frame select 9
> 
> frame #9: 0x000000010020bab4 emacs`adjust_markers_for_insert(from=1,
> from_byte=1, to=15403, to_byte=15413, before_markers=false) at insdel.c:294:
> 7
>    291   adjust_suspend_auto_hscroll (from, to);
>    292   for (m = BUF_MARKERS (current_buffer); m; m = m->next)
>    293     {
> -> 294       eassert (m->bytepos >= m->charpos
>    295        && m->bytepos - m->charpos <= Z_BYTE - Z);
>    296
>    297       if (m->bytepos == from_byte)
> (lldb) p *(struct Lisp_Marker *) m
> (struct Lisp_Marker) $1158 = {
>   header = (size = 4611686018477740032)
>   buffer = 0x00000001026b2718
>   need_adjustment = false
>   insertion_type = true
>   next = 0x00000001026f5f70
>   charpos = 0
>   bytepos = 11043
> }

??? charpos = 0?  How can that happen?  charpos can never be zero, it
starts at 1.

Are you sure your machine doesn't have problems with its memory chips?